Hoq Cave is one of the largest cave systems in the Arabian Peninsula, a 3-kilometre deep system in the limestone cliffs of Socotra's northeastern coast. Visitors can explore up to about 1 kilometre of the cave on foot, where massive stalactite and stalagmite formations rise in chambers tall enough to walk through without stooping. The cave maintains a humid, cool environment very different from the arid island above.
The walk to the cave entrance involves a steep climb up the coastal escarpment, with views along the rocky northern coast. A local guide is necessary; the cave is not marked and the interior is genuinely dark. The ancient inscriptions near the entrance are a remarkable side attraction for anyone interested in maritime history — they represent one of the most remarkable multilingual assemblages of ancient graffiti in existence.